Can opener



Jan. 4, 1938. R. T. KILLMAN CAN OPENER Filed Aug. 28, 1935 Patented Jan. 4, 1938 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to can openers of the smallhand type as distinguished fromthe larger types which are designed to be more or less permanently and rigidly attached to some stationary object such as a table, wall and the like.

It is among the objects of this invention to provide a can opener which retains the advantages of previous types such as cheapness and economy of manufacture, the cutting out of the head of the can so as to leave a smooth edge which will not be dangerous to anyone handling the can nor impede the emptying of the contents from the can, leaving the rim on the can so that the contents will not spill, ease of operation, and the like.

A further object of my invention is to provide a can opener by which the operations necessary to open a can are reduced to an absolute minimum. During the whole operation no part of the device need be touched except the handle and it is necessary to'turn the handle in one direction only to complete the whole operation of inserting the blade into the can head, cutting the can head out of the can, and removing the blade from engagement with the can rim or head so that the device may be removed from the can.

When the deviceis first picked up by the handle all of the parts are yieldably held in the proper position for placing the device on the rim of the can. No adjustments or placements of parts such as making sure the blade and feed wheel are in their separated position, and the like, are necessary. The handle and frame are yieldably held relative to each other in a stable, semi-rigid condition so that all parts are supported in the proper position for placement on the rim of a can by merely holding the handle.

This semi-rigid but yieldable positioning of the frame, handle and other parts relative to each other in a predetermined relationship accounts for the fact that after the device is placed on the rim of the can, the first turning movement of the handle causes the blade to puncture the head of the can. No preliminary turning of the handle is necessary to bring the parts into the proper positionto cause the blade to puncture the can head, as is the case with previous devices of this character. The first turning movement of the handle causes the blade to puncture the head of the can and further turning causes the device to move around the can, the blade shearing the head of the can close to the 'head.

When the blade has cut all the way around the can and cuts into the opening where it first punctured the can head, the blade is automatically withdrawn and the device maybe removed read ily from the can without any further operations such as reversing the rotation of the handle, moving a lever or the like.

From start to finish the whole operation of 5 holding the device in position to place it upon the rim of a can, the placing it thereon, the puncturing of the head, the cutting out of the head, the withdrawal of the blade, and removal of the device from the can is performed without the 10 necessity of touching or manipulating any part of the device except the handle, and that is turned in one direction only.

My method of accomplishing the above and other objects is explained in the following speci- 15 fication together with the accompanying drawing which shows a preferred embodiment of my invention and which:

Fig. 1 is a view of the blade side of my device with all parts in the stable, semi-rigid position, 20 ready for placement on the can which they normally occupy when the device is not in use.

Fig. 2 is a sectional view of the device taken along the line 2-2 of Fig.1.

Fig. 3 is a View of my device from the handle side. The solid lines show the handle member, the blade and its associated actuating members in the same stable semi-rigid position as shown in Fig. 1. The dotted lines show the blade and its associated actuating members in the position they occupy during the cutting operation.

Fig. 4 is a perspective view of a bearing washer used in mounting the feed wheel.

Fig. 5 is a perspective view of the coil spring used in my device;

Fig. 6 is a perspective view of a retaining washer used in mounting the feed wheel.

Fig. 7 is a view of my device from the handle side showing the device in place upon a can with all parts in the position they occupy just after the blade has been forced through the can head.

Fig. 8 is an end view of the device in place on a can which is shown in section. All parts are shown in the stable semi-rigid position which they occupy when the device is placed upon the can and just before the blade is forced through the can head.

Fig. 9 is a perspective view of the square shank rivet used in mounting the cutter blade.

'Fig. 10 is a perspective view of a bearing washer used in mounting the cutting blade.

Fig. 11 is a perspective view of a spacing washer used in mounting the cutting blade and its actuating member.

Fig. 12 is a perspective view of the blade actuating member.

Referring now to the drawing the numeral 20 designates a frame stamped from sheet metal. A tongue 22 is turned outward from the lower end to form a lower can guide. A tongue 2| is turned outward in the same direction to form an upper can guide. The frame is offset at 23 on a hori zontal line an amount approximatelyequal to its thickness. The frame 20 is provided with an upper hole for the blade assembly and a lower hole for the feed wheel and handle assembly.

The feed wheel assembly comprises a key handle 24 formed from sheet metal and provided with a tongue 25. Corners 26 and 21 are formed integral with the handle and provide a fiat working surface on either side of the handle, the purpose of which will be explained later. A toothed feed wheel 28, provided with a centrally located rectangular slot 29 with one side thereof slightly countersunk or flared, is mounted on the frame 20 on the same side thereof as that from which the tongues 2| and 22 project. A bearing washer 33 of a thickness slightly greater than the thickness of the frame 29 occupies loosely the lower hole in the frame 29. Washer 30 is also provided with a centrally located rectangular slot 3|. Mounted on the opposite side of frame 20 to that on which the feed wheel 28 is located, is positioned the retaining washer 32, also provided with a centrally located rectangular slot 33. The tongue 25 is designed to fit and to pass through the aligned rectangular slots in the washers 30 and 32 and the feed wheel 28. The end of the tongue is formed into a head 34 which fills the countersunk portion of the slot in the feed wheel 28. Thus there is formed an assembly whereby rotation of the handle 24 causes rotation of the feed wheel 28, the inner edge of the lower hole in the frame 20 and the outer edge of washer 30 acting as radial bearing surfaces, and the inner surfaces of feed wheel 28 and washer 32 cooperating with the surfaces of frame 20 to form thrust bearing surfaces. The feed wheel, as it comes from the die has the outer ends of the teeth slightly rounded or chamfered on one side. If this side is placed in contact with the surface of frame 20 no trouble will be had due to the teeth or burrs thereon cutting or scoring the surface of frame 20, and no spacing washer between the feed wheel and the frame will be necessary.

The cutter assembly comprises a blade 35 cut from strip stock and provided with a square hole 36. The lower end of the blade is formed as shown into an inclined shearing edge 31 and a piercing point 38. Blade 35 is located on the upper offset portion of the frame 20 opposite the hole therein, and on the same side of the frame 20 as the feed wheel 28 is located. A bearing washer 39, of thickness slightly greater than that of the frame 28, and provided with a centrally located square hole 40, fits loosely in the upper hole in the frame 20 for rotation therein. On the opposite side of the frame 29 to that upon which blade 35 is located, is positioned the spacing washer 4| provided with the centrally located square hole 42. Spaced from frame 20 by washer 4| is the blade actuating member 43 of substantially the shape shown, the circular portion of which is provided with the centrally located square hole 44. The depending finger portion of member 43 is provided with the straight edge 45, the purpose of which will be explained later. A rivet having a round head 46 and a shank 41, of square cross section is designed to fit into and to pass through the aligned square holes in the blade 35, washers 39 and 4|, and member 43. The end of the rivet is headed over at 48. The square holes in the blade 35 and the member 43 are so oriented with respect to the respective members that when assembled as described above the long axis of the blade lies at approximately a 45 degree angle from the straight edge 45 of member 43. Thus the blade 35,the washers 39 and 4 ,themember 43, and the rivet 41 comprise a rigid unit rotatable in the upper hole in frame 20, the outer edge of washer 39 and the inner edge of the hole forming radial bearing surfaces, and the inner faces of the blade 35 and washer 4| together with the two faces of the frame member 20 forming thrust bearing surfaces.

The rotary movement of this assembly is limited in both directions. In one direction rotation is limited by the edge 49 of the blade 35 coming into contact with the edge 50 of tongue 2|, this position being the cutting position of the blade. In the other direction rotation is limited by the straight edge 45 of blade actuating member 43 coming in contact with the flat portion on either of the sides of the key handle 24 between the corners 26 and 21. This position is the normal open or can-receiving position.

A torsion spring 5| having a hooked end 52 for engagement with blade actuating member 43, and a bent end 53 adapted for insertion in a hole 54 in the upper end of frame 20, urges the rotation of the blade assembly in the direction to bring the straight edge 45 of the blade actuating member 43 into contact with the flat surface on the handle 24 between the corners 26 and 21.

This spring urged contact is a very important part of my invention since it performs several very important functions in the operation of my device. The whole device is held in a stable, semi-rigid unit with no loose parts that must be held in place manually. The frame member has no tendency, as it would otherwise have, due to its top heaviness, to assume an upside down position when the device is lifted by the handle, preparatory to placing it on the rim of a can. Also the blade is held in its furthest separated position from the feed wheel, making insertion of the head of the can between them very easy. Also due to the straight edge 45 being yieldably held in contact with the fiat surface of the handle when the device is first placed upon the can, the very first turning movement of the handle causes the blade to be forced downward and through the metal of the can head. The spring tension also causes the blade 35, when it has out completely around the can and into its first incision in the can head, to be turned to its open or separated position with respect to the feed wheel 28, thus allowing removal of the device from the can without further manipulation.

The operation of the device is as follows: The operator picks up the device, holding it by the handle 24, all parts being in the position shown in Fig. 1 and the solid lines in Fig. 3, and places it on the can as shown by Fig. 8, the blade point 38 of the blade 35 being hooked over the can bead, the lower outer portion of which rides on the upper edge of the feed wheel 28. The operator then turns the key handle 24, whereupon the corner 26 on the handle 24, turning against edge 45 on member 43 causes member 43 to be turned outward. Member 43, through the medium of the square shank rivet 41 turns blade 35 and forces point 38 through the metal of the can head, the position of parts of the device then being as shown in Fig. 7. Further turning of handle 24 causes the device to be fed around the can, the pressure of the metal being sheared, against the edge 31 of blade 35 causing the blade 35 and its associated parts to move 7 to the position shown by the dotted lines in Fig. 3. Further turning of the handle causes the device to be fed around the can, cutting out the head. When the head is completely out out, there being no further pressure against edge 31, spring turns the blade assembly back to its original position, and the device may be easily removed from the can.

I have found that by slightly thinning the metal of the frame 20 along the offset line 23 sufiicient resiliency may be provided, together with that inherent in the blade and other parts, to allow the blade to adapt itself and conform to such slight defects and irregularities in cans as are met with in ordinary operation, no special means for this purpose being necessary.

While I have shown and described one specific form of my invention which, in practice, has been found to satisfactorily effectuate the stated purposes and objects thereof, it is manifest that the structural details may be considerably varied without involving any departure from the principle of the invention, and hence I do not limit the latter to the device as shown, except to the extent indicated in specific claims.

I claim:

1. The combination, in a can opener, of a frame; a feed wheel; an operating handle; a blade; a blade actuating member extending into the path of the handle, said blade actuating member having a straight edge adapted to cooperate with a flat surface on said handle; and resilient means urging said straight edge against said flat surface, whereby said blade and said handle are yieldably held in a predetermined can receiving position.

2. The combination in a can opener of a frame, a cutting blade rotatably mounted on the frame, an operating handle rotatably mounted on the frame, a blade actuating member extending into the path of the handle, so that when the handle is turned the blade will be caused to puncture the can, said blade actuating member being provided with a substantially straight edge on the side adjacent the handle, and said handle being provided with an unobstructed, substantially flat surface designed to cooperate with said straight edge, and a spring yieldably urging said straight edge to contact and press against said flat surface, whereby the blade is yieldably retained in can receiving position and the frame and handle are yieldably supported relative to each other so that said handle normally occupies a predetermined position relative to the frame, said position being one well adapted to serve as a starting point for the operation of the device.

3. The combination in a can opener, of a frame arranged to be applied to the edge of a can; a

traction member consisting of a toothed wheel, a shaft and a handle; a blade mounted for rotation on the frame and arranged to engage and cut a can; a blade actuating member associated with the blade and extending into the path of the handle of the traction member, so that, when the handle is turned, the blade will be forced against the can and as the movement continues the blade will puncture the can and then cut it; a flat surface carried by the handle of the traction member; a straight edge carried by the blade actuating member and arranged normally to bear against said flat surface; a spring member yieldably urging said straight edge and said flat surface into contact, whereby the handle and the blade are normally yieldably retained in a predetermined can receiving position.

4. In a can opener of the type described a frame member having in its upper part a circular bearing aperture, a square shaft passing through said aperture, a bearing bushing having a square hole located on said shaft and in said aperture whereby said shaft is journalled for rotation in said aperture, a cutting blade for cutting a can top mounted on one end of said shaft and upon one side of said frame, a blade actuating member mounted on the opposite end of the shaft and on the opposite side of said frame, a spacing washer located between said blade actuating member and said frame and serving to space said member and frame apart, and a coil spring encircling said spacing washer and having one end engaging the blade actuating member and the other end engaging the frame to normally rotate said blade actuating member and its associated members in one direction, and, a stop carried upon the frame for limiting said rotation.

5. In a can opener the combination of a frame having can guides formed integrally therewith, a cutting blade mounted on the frame for cutting the can head, a shaft on which said cutting blade is mounted journalled in the frame, a blade operating member mounted on the opposite end of said shaft, a coil spring disposed about said shaft and having one end engaging the blade operating member to normally rotate the latter in one direction, the other end of said spring passing through a hole in the frame, a traction wheel mounted on the frame to engage the bead of a can, a shaft on which said traction wheel is mounted journalled in the frame, handle means connected with said shaft for rotating it, said handle being provided with a flat portion and said blade operating member being provided with a straight edge for cooperating with said fiat surface, said straight edge being yieldably held in contact with said flat surface over substantially the entire width of the surface by the said coil spring, whereby the handle member and the blade member are yieldably retained in a predetermined can receiving position.

ROBERT T. KILLMAN. 

